Robustness to low-wind effect errors between petals. Left: phase maps simulated in the pupil plane in radians. Right: associated PSFs in logarithmic scale with the three designs. Four phases are considered (from top to bottom): no error; piston-only errors, at the level observed on SPHERE before coating; tip-tilt-only errors, also at the SPHERE level; combined piston-tip-tilt errors from the above lines.